naked functions: respect function_sections on windows

For `gnu` function_sections is off by default.

Author: folkertdev

compiler/rustc_codegen_ssa/src/mir/naked_asm.rs

@@ -128,6 +128,8 @@ fn prefix_and_suffix<'tcx>(
 
     let is_arm = tcx.sess.target.arch == Arch::Arm;
     let is_thumb = tcx.sess.unstable_target_features.contains(&sym::thumb_mode);
+    let function_sections =
+        tcx.sess.opts.unstable_opts.function_sections.unwrap_or(tcx.sess.target.function_sections);
 
     // If we're compiling the compiler-builtins crate, e.g., the equivalent of
     // compiler-rt, then we want to implicitly compile everything with hidden
@@ -278,8 +280,11 @@ fn prefix_and_suffix<'tcx>(
             writeln!(begin, ".type 32").unwrap();
             writeln!(begin, ".endef").unwrap();
 
-            let section = link_section.unwrap_or_else(|| format!(".text.{asm_name}"));
-            writeln!(begin, ".pushsection {},\"xr\"", section).unwrap();
+            if let Some(section) = &link_section {
+                writeln!(begin, ".pushsection {section},\"xr\"").unwrap()
+            } else if function_sections {
+                writeln!(begin, ".pushsection .text${asm_name},\"xr\"").unwrap()
+            }
             write_linkage(&mut begin).unwrap();
             writeln!(begin, ".balign {align_bytes}").unwrap();
             writeln!(begin, "{asm_name}:").unwrap();

tests/codegen-llvm/naked-fn/naked-functions.rs

@@ -1,12 +1,14 @@
 //@ add-minicore
-//@ revisions: linux win_x86 win_i686 macos thumb
+//@ revisions: linux win_x86_msvc win_x86_gnu win_i686_gnu macos thumb
 //
 //@[linux] compile-flags: --target x86_64-unknown-linux-gnu
 //@[linux] needs-llvm-components: x86
-//@[win_x86] compile-flags: --target x86_64-pc-windows-gnu
-//@[win_x86] needs-llvm-components: x86
-//@[win_i686] compile-flags: --target i686-pc-windows-gnu
-//@[win_i686] needs-llvm-components: x86
+//@[win_x86_gnu] compile-flags: --target x86_64-pc-windows-gnu
+//@[win_x86_gnu] needs-llvm-components: x86
+//@[win_x86_msvc] compile-flags: --target x86_64-pc-windows-msvc
+//@[win_x86_msvc] needs-llvm-components: x86
+//@[win_i686_gnu] compile-flags: --target i686-pc-windows-gnu
+//@[win_i686_gnu] needs-llvm-components: x86
 //@[macos] compile-flags: --target aarch64-apple-darwin
 //@[macos] needs-llvm-components: aarch64
 //@[thumb] compile-flags: --target thumbv7em-none-eabi
@@ -23,6 +25,11 @@ use minicore::*;
 //
 // linux:    .pushsection .text.naked_empty,\22ax\22, @progbits
 // macos:    .pushsection __TEXT,__text,regular,pure_instructions
+//
+// win_x86_msvc:     .pushsection .text$naked_empty,\22xr\22
+// win_x86_gnu-NOT:  .pushsection
+// win_i686_gnu-NOT: .pushsection
+//
 // thumb:    .pushsection .text.naked_empty,\22ax\22, %progbits
 //
 // linux, macos, thumb: .balign 4
@@ -35,12 +42,12 @@ use minicore::*;
 //
 // linux: .type naked_empty, @function
 //
-// win_x86:  .def naked_empty
-// win_i686: .def _naked_empty
+// win_x86_msvc,win_x86_gnu:  .def naked_empty
+// win_i686_gnu: .def _naked_empty
 //
-// win_x86,win_i686: .scl 2
-// win_x86,win_i686: .type 32
-// win_x86,win_i686: .endef
+// win_x86_msvc,win_x86_gnu,win_i686_gnu: .scl 2
+// win_x86_msvc,win_x86_gnu,win_i686_gnu: .type 32
+// win_x86_msvc,win_x86_gnu,win_i686_gnu: .endef
 //
 // win_x86:  .pushsection .text.naked_empty,\22xr\22
 // win_i686: .pushsection .text._naked_empty,\22xr\22
@@ -59,7 +66,8 @@ use minicore::*;
 // linux,macos,win_x86,win_x86: ret
 // thumb: bx lr
 //
-// linux,macos,thumb: .popsection
+// linux,windows,win_x86_msvc,thumb: .popsection
+// win_x86_gnu-NOT,win_i686_gnu-NOT: .popsection
 //
 // thumb: .thumb
 //
@@ -82,6 +90,11 @@ pub extern "C" fn naked_empty() {
 //
 // linux:    .pushsection .text.naked_with_args_and_return,\22ax\22, @progbits
 // macos:    .pushsection __TEXT,__text,regular,pure_instructions
+//
+// win_x86_msvc:     .pushsection .text$naked_with_args_and_return,\22xr\22
+// win_x86_gnu-NOT:  .pushsection
+// win_i686_gnu-NOT: .pushsection
+//
 // thumb:    .pushsection .text.naked_with_args_and_return,\22ax\22, %progbits
 //
 // linux, macos, thumb: .balign 4
@@ -94,12 +107,12 @@ pub extern "C" fn naked_empty() {
 //
 // linux: .type naked_with_args_and_return, @function
 //
-// win_x86:  .def naked_with_args_and_return
-// win_i686: .def _naked_with_args_and_return
+// win_x86_msvc,win_x86_gnu:  .def naked_with_args_and_return
+// win_i686_gnu: .def _naked_with_args_and_return
 //
-// win_x86,win_i686: .scl 2
-// win_x86,win_i686: .type 32
-// win_x86,win_i686: .endef
+// win_x86_msvc,win_x86_gnu,win_i686_gnu: .scl 2
+// win_x86_msvc,win_x86_gnu,win_i686_gnu: .type 32
+// win_x86_msvc,win_x86_gnu,win_i686_gnu: .endef
 //
 // win_x86:  .pushsection .text.naked_with_args_and_return,\22xr\22
 // win_i686: .pushsection .text._naked_with_args_and_return,\22xr\22
@@ -115,14 +128,15 @@ pub extern "C" fn naked_empty() {
 //
 // CHECK-LABEL: naked_with_args_and_return:
 //
-// linux, win_x86,win_i686: lea rax, [rdi + rsi]
+// linux,win_x86_msvc,win_x86_gnu,win_i686_gnu: lea rax, [rdi + rsi]
 // macos: add x0, x0, x1
 // thumb: adds r0, r0, r1
 //
 // linux,macos,win_x86,win_i686: ret
 // thumb: bx lr
 //
-// linux,macos,thumb: .popsection
+// linux,windows,win_x86_msvc,thumb: .popsection
+// win_x86_gnu-NOT,win_i686_gnu-NOT: .popsection
 //
 // thumb: .thumb
 //
@@ -146,7 +160,7 @@ pub extern "C" fn naked_with_args_and_return(a: isize, b: isize) -> isize {
 
 // linux:            .pushsection .text.some_different_name,\22ax\22, @progbits
 // macos:            .pushsection .text.some_different_name,regular,pure_instructions
-// win_x86,win_i686: .pushsection .text.some_different_name,\22xr\22
+// win_x86_msvc,win_x86_gnu,win_i686_gnu: .pushsection .text.some_different_name,\22xr\22
 // thumb:            .pushsection .text.some_different_name,\22ax\22, %progbits
 // CHECK-LABEL: test_link_section:
 #[no_mangle]
@@ -163,15 +177,15 @@ pub extern "C" fn test_link_section() {
     }
 }
 
-// win_x86:  .def fastcall_cc
-// win_i686: .def @fastcall_cc@4
+// win_x86_msvc,win_x86_gnu:  .def fastcall_cc
+// win_i686_gnu: .def @fastcall_cc@4
 //
-// win_x86,win_i686: .scl 2
-// win_x86,win_i686: .type 32
-// win_x86,win_i686: .endef
+// win_x86_msvc,win_x86_gnu,win_i686_gnu: .scl 2
+// win_x86_msvc,win_x86_gnu,win_i686_gnu: .type 32
+// win_x86_msvc,win_x86_gnu,win_i686_gnu: .endef
 //
-// win_x86-LABEL: fastcall_cc:
-// win_i686-LABEL: @fastcall_cc@4:
+// win_x86_msvc-LABEL,win_x86_gnu-LABEL: fastcall_cc:
+// win_i686_gnu-LABEL: @fastcall_cc@4:
 #[cfg(target_os = "windows")]
 #[no_mangle]
 #[unsafe(naked)]